Ascites may be accumulated in the abdominal cavity because of peritonitis, cirrhosis, cancer, etc. Among various measures to deal with the ascites, one measure is to reduce ascites by forcibly draining water in the body as urine using diuretics, and another measure is to directly remove ascites by inserting a tube in the abdominal cavity. However, since ascites includes leukocytes, proteins, etc., it is not preferable in many cases that ascites is drained from the body simply.
Therefore, a method of placing a catheter in the body for the purpose of returning ascites back into the body without draining the ascites has been put into practical use. The abdominal cavity-vein shunt catheter has a chamber provided with a check valve, a venous tube connected to one end of the chamber, and an abdominal cavity tube connected to the other end of the chamber.
To place the abdominal cavity-vein shunt catheter, first, a pocket for placing the chamber is provided by puncturing the subclavian vein, and a distal end of the venous tube is attached to an insertion jig called tunneler. Then, the tunneler is inserted from a predetermined portion of the abdominal cavity and pushed through the hypodermis, the chamber is placed in the pocket, and the distal end of the venous tube is inserted into the vena cava via the subclavian vein while the abdominal cavity tube is placed in the abdominal cavity. When the pressure in the abdominal cavity increases, the check valve of the chamber is opened, thereby transporting ascites to the vein.
In the abdominal cavity-vein shunt catheter, because the placement range thereof is wide and the tunneler is pushed through the hypodermis, the physical load imposed on the patient is heavy. Further, there is a possibility that the catheter may be damaged by body motion, an external injury, etc.
In view of above, the present applicant has devised an abdominal cavity-vein shunt catheter to lighten the physical load imposed on a patient. Patent Literature 1 discloses, as such a catheter, an abdominal cavity-vein shunt catheter which has an ascites inlet provided at one end portion and/or at a side portion near one end portion, an outlet provided at an intermediate portion to communicate with the right atrium or the vena cava, and a check valve provided in the outlet so as to be opened when the catheter internal pressure compared with the external pressure is higher than a predetermined value but to be closed when the catheter internal pressure is lower than the predetermined value. The catheter is implanted in the body such that the catheter is inserted from the right subclavian vein to pierce the liver through the right atrium, the vena cava and the right hepatic vein and to be led into the peritoneal cavity, and the other end is closed after the implantation. Thus, the catheter is used in the condition that the inlet is placed in the peritoneal cavity while the outlet is located in the vein.
According to the abdominal cavity-vein shunt catheter, because the catheter can be implanted in a relatively narrow range of from the right subclavian vein to the peritoneal cavity without passing through the hypodermal tissue, the physical load imposed on a patient at the time of placement of the catheter can be lightened significantly compared with the background-art abdominal cavity-vein shunt catheter placed through the hypodermis.